Filtering device



w. o. VEDDER FILTERING DEVICE Filed April 19, 1962 Jan. l2, 1965 INVENTOR /Lmme ATTORNEYS` United States vPatent 2O.

3,165,389 FILTERNG DEVKCE Walter 0. Vedder, Hagerstown, Md., assigner, by mesne assignments, to The Paugborn Corporation, Hagerstown, Md., a corporation of Delaware Filed Apr. 19, 1962, Ser. No. 138,659 Claims. (Cl. 55-394) vThe present invention relates to a cleaning device.

- More specifically, to a filtering device for the removal of particulate matter from gaseous material.

It is generally known that particulate material such as dust may be conveniently removed from air or other Ygasses by simply passing the gases through porous cloth filters. Such filtering elements are relatively inexpensive, easy to use, and remarkably etlicient. Unfortunately,

filtering elements of this type tend to become clogged,

vthe iilters are used.

It is an object of the present invention to provide an improved cleaning arrangement for these iilters. l

The above and other objects are accomplished in accordance with the present invention by providing a filter exing assembly which is free of working joints.

j The details of the present invention will become more clearly apparent by referring to the accompanying drawings wherein:

FIG. l represents'a vertical section of one embodiment of the invention;

FIG. 2 is a sectional view taken along lines 22 of FIG. l;

FIG. 3 is a fragmentary detail of a modied embodiment;

FIG. 4 is a sectional view of a supporting element of the constructions of FIGS. l-3; and

FIG. 5 represents an enlarged fragmentary detail of a modication of the invention showing a double air bag arrangement. v

In FIG. l is shown a filter device having a housing 5 equipped with hopper 7, gas inlet port 9, baffle 1G, oor 48, gas outlet port 33, and'filtering elements 11 in the form of fabric filter tubes A12 supported at their tops from movable frame 14 by attachments 15. These attachments can be of any type such as shown for example in U.S. Patent 2,667,233, granted January 26, 1954. Movable frame 14 is, in turn, supported on brackets 17 by means of resilient gas cushions 19. v

Movable frame 14 consists of principal bars 16 running lengthwise ofthe housing and a plurality of secondary bars 18 connected between the principal bars and having struction, a single nut Vcan beused with each bar to merely holdeach tube under tension. Such a single nut modiiiice cation is desirable since it simplifies the installation of the tubes Ias well as their removal for maintenance purposes and the like. Clamps 46 can be used to securely anchor the upper ends of the tubes around the heads 40.

The lower end of tubes 12 can be conveniently clamped by clamps 46 to a plurality of open circular flange extensions 35 of a perforated lioor piece 48. Each iiange is arranged laround a perforation and may be conveniently secured to floor 43 by welding, bolting, or can be cast together with the iioor piece as a unit. Floor piece 4S is, in turn, secured to housing 5 to effect a substantially air tight seal by welding or byl bolting thereto.

An alternative securing arrangement for tube 12 is shown in United States Patent 2,143,664, granted January 10, 19,39, in which springy rings are sewn into a hem at the lower end of tube 12 andthe springy ends are pushed through perforations in a floor piece. For this purpose, each hole can be a little smaller in diameter than the normal size of the ring, so that the ring must be sprung into the hole and will then expand to securely anchor the bag hem against the margin of the hole.

Each of the passageways 31 in the individual cushions connects with a supply conduit 50 by means of which the pressure within the cushions cany becontrolled, using a source of pressure or suction or both.

The lower end of hopper '7 is closed as by a trap door or revolving door type closure to permit Withdrawal of the solids that collect in the hopper.

In FIG. 3 is shown a different arrangement of the invention in which the cushion-holding brackets 17 are 'a lower plate 27. Wells 29 are provided in the plates las by Welding for the purpose of threaded attachment to supporting bracket 17, and a passageway 3l is provided for removing or adding acuating fluid to .the interior of the cushions.

In FIG. 5 is shown amodiication of the arrangement of FIG. 3 in which opposing gas cushions 19 and 19A are mounted on either side of frame bar 16, between supporting brackets 17 and 17A. This arrangement provides a convenient means for varying the frequency and amplitude of longitudinal displacement of the fabric tubes l during the cleaning cycle.

In operation a stream of particle-laden gas such as dusty air is introduced through intake port 9 so that it passes through filtering elements 11. In such passage the particles suspended in the gas are trapped on the inner surfaces ofthe fabric tubes, and particle-free gas is discharged through gas outlet port 33. When so many particles have collected on the inner surfaces of the ilter tubes that the flow of gas is diminished, the tubesare readily and elfectivel-y rejuvenated by merely changing `the pressure in the air cushions, preferably a multiplicity of times in fairly rapid sequence. VBy way of example, a three-way valve 60 (ref. FIG. 1) can be Ypressure in theupper or opposing cushion.

conduit to a source of pressurized air as from aV highkpressure .storage tank, or it can openconduit 5t) to theV external atmosphere. The three-way valve can then a merely be shifted between ,the above two positions.

,v connected to conduit 50 so-that it Vcan either expose the Y23, the construction of FIG. 3

' since itn removes this elementfrorn thefinteriorof the For the purpose of the present invention, about three i pressure pulses per second Vfor a period of about ten to The term natural frequency as applied to the inven-Q tion refers tothe number of cycles (i.e. vented to full to vented) thatV the supporting cushions can makein a given period without employing outside forces to hasten t housing. Flexible boot 2l also aids in protecting the cushion from suchfluid. When'filtering very Vhot gases, N

for instance, the filter tubes ilZcan bernade of glass, of synthetic fibers or the'like sincethey are Vresistant to high temperatures, and `thev air Vcushions externally positionedV and therefore, made of rubber or similar material that the exhaustion of gases from `the supporting'cushions.

In the present case, theV natural frequency generally falls Within the range of about 100 to 2,00 cycles per minute. If external means for increasing vtheV vent rate are em# varied substantially outside of this range.v

Y When the device is in operation, the ,effect ofrrapidV f pressure variation within the supporting cushions causes the upper frame i4 to move in a vertical reciprocal motion,

lcausing -lter tubes' 12 toalternatelyVY stretch and'rclax.Y Y The stretching is preferably restricted to a longitudinal displacement of about .4% to .8% of the Vtube length.

In a preferred 120 inch tube, thisjrequhes `a stroke' sub\` ployed, however (ref. FlG. 5),-the frequency may be stantially within the range of about one-half inch to cnegf,

inch. Such flexing is found to rapidly loosen the particles collected Yon `the inside surfaces of the tube and permits the particles to fall into hopper '.7.

need not be resistant vto the highv temperatures Within the housing. Instead 'of having the resilientmembers made of rubber, they can be'made ofother materials such as plastic, leatlieror the'iike, or thefcushioning canl be provided by piston and cylinder combinationsconstructedY entirely ofrnetai;v

Regardlessof which of these alternative cushion arrangements vis used, theyy are all free of mechanical working jointssuch asi pivots,andlthey accordingly show. an kextremelylong lifewith'exceedingly l little maintenance requirements.l This is particularly. important `because commercial filter,installationsV of this .type are generally located where they are [not easily Vreached for maintenance purposes, and vin addition, the housings are usually-packed full ofiilter tubes so Vthat it is not a simple matter Vto conductmaiintenance within the housingk even when they are accessible.

The activating Vhuid employed 'intl'i'epresent invention may be a gas or liquid such as air, nitrogen, water, `cornmercialhydraulic fluids, or rnaterials'of similar nature `V Well known tothe art, provided they-vare inertand relatively stablev under normal operatinglconditions.

The cleaning,:-actionisalso,improved vbyjarriiig or rapidly stopping theffrarne 14, .preferably at :the end of each ofY its upward movements. v11n-'convenient arrange-V 4, ment for accomplishing AthisV is -to mountone orgmore During the cleaning cycle, the device is conveniently shut down by, temporarily closing port 33', Yif an exhaust arrangement is employed or by closing port 9 if positive.` pressure is used. Such a valving'.,arrangernent Vis not4 shown in the figures, however, a number of suitable'conif mercial valves are available for this'purpose.

`to i, the above-described details without'.departing'from the A shut down may be lavoided and a'reversal of iiow` conveniently obtainedyif` desired, by connectingtwo or more units of the. type shown in YElGS; r1 and 2, in parallel so that vboth have their inlet ports 9 su'jgipiiedV by the same t source of particle-containing gas andfboth" have theirv Y, outlet ports 33 connected to suction sources,

' suchsuction sourcesoperating in such connection, both AWith both units will effect iiltering, and when vone suctionV .source is disconnected fromv the-corresponding outlet port 33 fixed vlimit* stopV-r above the frame member;to'limitV its upward traveLw-"ihe stops can provide'meta1tonietal Y Contact vwith the 'fr'anievto give very abruptaction," or they can have va somewhat yieldable action 'as by beingrrriade Y V`of a block of dense rubber.

Sincemany changesaiid modifications can be made Yin nature and spirit of 'thefinventiom itis to' be understood that the invention is Ynot to be limited 'except a's-'set forth in the appended 'claimslpv f I .What is claimed: Y

`1. A diist collecting Y apparatiisi'for filtering and-col? Y iectingparti'culate matter from gas comprising a chainand the port opened tothe surroundingiairythesuction applied from the other source will be communicated to,`

theV inlet Vport 9 of the housing disconnected from its own f suctionfsource, and Ywill in this manner reverse the iiow of gas. j

simultaneously changing the-pressure inthe individual cushions in the saine manner,"-or by'having dierentl cushions undergo different changesjso that thegupper frame i4 goes through some twisting motions. lnrsuch -a modi-V fioation, the cushions on one side of the trame are con-k nected 'to a vpulsed pressure-decreasing source.

Y Y Y 5s The flexing of the iilter tubes can also be effected yby The cushions can Ythen be made offsuchy inherent'stiiiness;

, that Vin the absenceV of they pressuredecrease' they keep the s' f 1 filter tubes stretchedby atleast a small amount.

Opposing cushionstref. FIG. 5) may Valso be utilized to obtain-asimilar effectby Vemploying a constant pressurevin theV supporting cushion memberandjvarying the arrangement a Ahigher frequency is also obtained.

The yapparatus of the 'presentav invention Vcan: be t usedV for filtering all kinds of uids. l i t WhereV the fluid being filtered 'would haveV an unde'sii' a Y able effect on the air cushioinas for example' chemically react'with or physically deteriorate. the resilient element By such an"V ber; a i'ioor inV said'fcharnbenY spacedf'openings inV said i fioor,.ra filter `tube support frame positioned inthe upper portion y-of said chamber, dustiltertubes supported by 50`k Y Y opposite ends `of the chamber forV supporting said frame, aircusliions connecting'- the vframe with saidS framesupsaid vframe meansY extending from the'chaniber'wall at port 'wall extensions, individual' means connected .with

, eachair cushion for inflating anddefiatingsaidcushion for 'flexing said dustrrtilter tubes, means on said frame directly securing the upper endsrof dust Afilter tubes thereto, means connecting the bottom ends v'of-said dustfilter tubes to they openings in the iioor vof Ysaid chamber, means for introducing dust lladen ,gasp to .a point .beneath ysaid i'ioor adjacent saidfloor. openings, and meansV connected with said chamber.. for drawingvv thedusty laden t gas through the dust iiltertubes and for'withdrawing the dustfreeY gas Vfromthechamberafter itV has passed A'through The apparatus oiV claim v1 vvhereiii:{the frame supporting Vthe dust ilterV tubesV is Vorinedfrofftwo elongated Vinem-bers extending longitudinally of the `chamber adjacent theV side walls thereofrand-crossbars'connected with the elongated meinbersiwhich crosslbars Vdirectly"support the upper endof said V'dust nltcrxtubes, Vsaid'longitudinal Y `members being connectedy at their'jends with" saidfr'iirY cushions'. 1

3L The apparatusofclaim wherein-.said Vofsaid `longitudinal meiiio'er'sare Vcoiiii'eicte'rd with Vair cushions i'sparticularly desirable Y which are in turn connected with internal chamber wall extension means.

4. The apparatus of claim 2 wherein the ends of said` longitudinal members extend through and beyond the chamber walls and are connected with air cushions positioned externally of the chamber, external chamber wall extension means being connected'to said air cushions, and exble seals are connected with the openings of the chamber wall through which the longitudinal members extend and to the longitudinal members themselves.

5. The apparatus of claim 4 wherein said cushions comprise pairs of upper and lower cushions, said external wall extension means being pairs of upper and lower chamber wall extension means, the ends of said longitudinal members being connected in sandwich manner to an upper and lower air cushion, and said cushions being also connected to upper and lower chamber Wall extension means.

Referencesl Cited in the le of this patent UNITED STATES PATENTS 1,153,751 Beth Sept. 14, 1915 2,143,664 ySnyder Jan. 10, 1939 2,667,233 Vedder Jan. 26, 1954 2,850,112 Dru Sept. 2, 1958 FOREIGN PATENTS 1,056,494 France Oct. 2.1, 1953 

1. A DUST COLLECTING APPARATUS FOR FILTERING AND COLLECTING PARTICULATE MATTER FROM GAS COM PRISING A CHAMBER, A FLOOR IN SAID CHAMBER, SPACED OPENINGS IN SAID FLOOR, A FILTER TUBE SUPPORT FRAME POSITIONED IN THE UPPER PORTION OF SAID CHAMBER, DUST FILTER TUBES SUPPORTED BY SAID FRAME MEANS EXTENDING FROM THE CHAMBER WALL AT OPPOSITE ENDS OF THE CHAMBER FOR SUPPORTING SAID FRAME, AIR CHUSHIONS CONNECTING THE FRAME WITH SAID FRAME SUPPORT WALL EXTENSIONS, INDIVIDUAL MEANS CONNECTED WITH EACH AIR CUSHION FOR INFLATING AND DEFLATING SAID CUSHION FOR FLEXING SAID DUST FILTER TUBES, MEANS ON SAID FRAME DIRECTLY SECURING THE UPPER ENDS OF DUST FILTER TUBES THERETO, MEANS CONNECTING THE BOTTOM ENDS OF SAID DUST FILTER TUBES TO THE OPENINGS IN THE FLOOR OF SAID CHAMBER, MEANS FOR INTRODUCING DUST LADEN GAS TO A POINT BENEATH SAID FLOOR ADJACENT SAID FLOOR OPENINGS, AND MEANS CONNECTED WITH SAID CHAMBER FOR DRAWING THE DUST LADEN GAS THROUGH THE DUST FILTER TUBES AND FOR WITHDRAWING THE DUSTFREE GAS FROM THE CHAMBER AFTER IT HAS PASSED THROUGH THE DUST FILTER TUBES. 